This invention relates to breakaway couplings, and in particular, a breakaway coupling which requires a considerable amount of force (i.e. 200 lbs.) to couple and uncouple.
Breakaway couplings are commonly placed in gas delivery hoses at gas stations. Examples of such couplings are shown in U.S. Pat. Nos. 5,365,973 and 4,827,977, which are owned by the same assignee as the instant invention, and which are incorporated herein by reference. As is known, such couplings are provided to stop the flow of gasoline through the hose should a customer inadvertently forget to remove the fuel delivery nozzle from his car before leaving a gas station. When breakaway couplings are used, should a customer forget to remove the nozzle, the coupling will separate, and the valves therein will close to prevent a gasoline spill. However, depending upon the force of the separation, the fuel dispensing equipment can be damaged. It is thus important that the fuel dispenser and its associated components be inspected by trained personnel prior to putting the pump back into service.
Current breakaway couplings, however, require very little force to put the coupling back together. For example, in the coupling of the above noted patents, the coupling can be connected with as little as 10 lbs. of force. When the breakaway coupling is disconnected, the customer may attempt to reconnect the coupling. To prevent a customer from reassembling breakaway couplings, shear pin safety breakaway couplings have been developed. However, typical shear pin safety breakaways have a higher separation force than a reconnectable safety breakaway. Thus, dispensing equipment is subjected to undue forces during a driveaway. Shear pin safety breaks are also susceptible to pin degradation. Such degradation is due to nozzle imparted line shock, and can result in nuisance separation.